Patients with deletions of distal 4p have the characteristic features of Wolf-Hirschhorn syndrome (WHS).
Wolf-Hirschhorn syndrome, also known as deletion 4p and 4p- syndrome was first described in 1961 by the Americans Herbert L. Cooper and Kurt Hirschhorn, and thereafter gained worldwide attention by publications by the German Ulrich Wolf, and Hirschhorn and their co-workers, specifically their articles in the German scientific magazine ’Humangenetik’.
It is a characteristic phenotype resulting from a partial deletion of chromosomal material of the short arm of chromosome 4.
Synopsis
profound mental retardation
microcephaly
seizures
poor muscle tone
cleft lip and/or cleft palate
strabismus
hypertelorism
bilateral microphthalmia (18551766)
orbital cysts (18551766)
posterior intraorbital coloboma cyst (15030910)
down-turned "fishlike" mouth
short upper lip and philtrum
small chin
ear tags or pits
cranial asymmetry
heart defects
hypospadias
scoliosis, ptosis
fused teeth
hearing loss
delayed bone age
low hairline with webbed neck
renal anomalies
multiple hemangiomas (18076104)
congenital diaphragmatic hernia (16903248)
cutaneous T-cell lymphoma (15103723)
Etiology
Wolf-Hirshhorn syndrome is caused by a partial deletion of the short arm of chromosome 4, particularly in the region of WHSC1 and WHSC2.
About 87% of cases represent a de novo deletion, while about 13% are inherited from a parent with a chromosome translocation.
In the cases of familial translocation, there is a 2 to 1 excess of maternal transmission.
Of the de novo cases, 80% are paternally derived. The symptoms and phenotype do not differ based on the size of the deletion.
The critical region for determining the phenotype is at 4p16.3 and can often be detected through genetic testing and fluorescent in situ hybridization (FISH).
Genetic testing and genetic counseling is offered to affected families.
References
Pardo S, Blitman N, Han B, Cohen N, Edelmann L, Hirschhorn K. Multiple hemangiomas in a patient with a t(3q;4p) translocation: an infrequent association with Wolf-Hirschhorn syndrome. Am J Med Genet A. 2008 Jan 15;146(2):219-24. PMID: 18076104